Reference voltage generating circuit and internal voltage generating circuit for controlling internal voltage level

Abstract

Provided are a reference voltage generating circuit and an internal voltage generating circuit for controlling an internal voltage level, where the reference voltage generating circuit includes a distributing unit, a clamping control unit, and a control unit; the distributing unit has a voltage level lower than that of an external power supply voltage in response to the external power supply voltage, and outputs via an output terminal a reference voltage which varies according to an operating mode; the clamping control unit is connected between the output terminal and a ground voltage, and clamps the voltage level of the reference voltage at a constant level in response to a control voltage having a voltage level which is lower than that of the reference voltage; the control unit increases or decreases the voltage level of the reference voltage in response to first and second operating mode signals; the control unit includes a first control transistor and a second control transistor; and the reference voltage generating circuit controls a reference voltage level according to an operating mode of the semiconductor memory device such that the operating characteristics of the semiconductor memory device can be improved in some operating modes and power dissipation can be minimized in other operating modes.